Ultrasmall BiOI Quantum Dots with Efficient Renal Clearance for Enhanced Radiotherapy of Cancer

Abstract

Emerging strategies involving nanomaterials with high‐atomic‐number elements have been widely developed for radiotherapy in recent years. However, the concern regarding their potential toxicity caused by long‐term body retention still limits their further application. In this regard, rapidly clearable radiosensitizers are highly desired for practical cancer treatment. Thus, in this work, ultrasmall BiOI quantum dots (QDs) with efficient renal clearance characteristic and strong permeability inside solid tumor are designed to address this issue. Additionally, considering that injection methods have great influence on the biodistribution and radiotherapeutic efficacy of radiosensitizers, two common injection methods including intratumoral injection and intravenous injection are evaluated. The results exhibit that intratumoral injection can maximize the accumulation of radiosensitizers within a tumor compared to intravenous injection and further enhance radiotherapeutic efficacy. Furthermore, the radiosensitizing effect of BiOI QDs is revealed, which is not only attributed to the radiation enhancement of high‐Z elements but also is owed to the •OH production via catalyzing overexpressed H2O2 within a tumor by BiOI QDs under X‐ray irradiation. As a result, this work proposes a treatment paradigm to employ ultrasmall radiosensitizers integrated with local intratumoral injection to realize rapid clearance and high‐efficiency radiosensitization for cancer therapy.

Reactive Oxygen Species‐Regulating Strategies Based on Nanomaterials for Disease Treatment

“…And they have developed many novel semiconductor‐catalytic nanomaterials to apply in triggering H 2 O 2 for ROS production under X‐ray irradiation, such as BiOI QDs, Au‐Bi 2 S 3 NPs and bismuth heteropolytungstate [BiP 5 W 30 O 110 ] 12‐ (BiP 5 W 30 ) nanoclusters. [ 203–205 ]…”

“…[ 226 ] Besides that, in recent years, many studies indicated that semiconductor nanomaterial with high‐Z elements can directly be activated by X‐ray for ROS generation via a radiocatalytic process, such as BiOI QDs, Bi 2 WO 6 , WO 3 ‐Ag 2 WO 4 NPs, Au‐Bi 2 S 3 NPs and bismuth heteropolytungstate [BiP 5 W 30 O 110 ] 12‐ (BiP 5 W 30 ) nanoclusters, etc. [ 203–205,254 ] In the radiocatalytic process, these semiconductor nanomaterial can generate a lot of e − –h + pairs under X‐ray irradiation. These highly active e − –h + pairs can react with adjacent molecules such as O 2 and H 2 O to enhance ROS generation.…”

“…[ 292 ] Here, vascular disruption can improve the blood vessel permeability by employing physical forces such as heat, US and radiation, as well as introducing vascular disrupting agents. [ 203,293–295 ] Vascular normalization for restoring blood supply is usually realized by using anti‐angiogenic agents to inhibit rapid formation of dysfunctional vascular networks, ultimately inducing homogeneous distribution of therapeutic agents inside tumor. [ 292 ] While for the modulation of ECM, it is mainly achieved through blocking the ECM synthesis or depleting ECM with the aid of nanosystems.…”

Palladium-based nanomaterials for cancer imaging and therapy

“…However, normal tissues surrounding the tumors often suffer serious damage under high dose ionizing radiation because of nonspecific interactions. Thus, radiosensitizers have been employed to enhance the effect of RT under low-dose ionizing radiation by increasing the radiosensitivity of tumor cells 84 . Similar to CT contrast agents, nanomaterials composed of high atomic number metals have been developed as potential radiosensitizers to enhance the efficiency of RT.…”

Energy‐converting biomaterials for cancer therapy: Category, efficiency, and biosafety

“…Cu‐based chemical‐driven ROS‐ECBs, such as Cu 2+ ‐doped biomaterials (Li et al, 2019; Liu et al, 2019a; Wang et al, 2019), copper sulfide (Pan et al, 2020; Wang et al, 2020), and Cu 2‐ x Se (Wang, Guo, et al, 2020), exhibited excellent performance in CDT compared with Fe‐based chemical‐driven ROS‐ECBs. It has been reported that the Cu + ‐catalyzed Fenton‐like reaction with the high reaction rate could occur in a wider range of pH compared with Fe 2+ (Wang et al, 2020).…”